Assigning children in visible trap does not fire child visible traps

[Charles Goodwin]

<ui:box display="false">
    <ui:box id="a" /> // not visible
    <ui:box id="b" /> // not visible
</ui:box>
<ui:box id="c" /> // visible

$a.visible ++= function(v) {
    cascade = v;
    vexi.log.info("a now visible? "+v);
    $a[0] = $b;
}

$b.visible ++= function(v) {
    cascade = v;
    vexi.log.info("b now visible? "+v);
}

// only outputs for $a, not $b
$c[0] = $a;

The code that handles surface/visible puts needs rewriting to make use of a Callable that:
- depth-first call preTriggerTraps for surface/visible
- assigns box to new parent
- depth-first call postTriggerTraps

[Charles Goodwin (charlesgoodwin)]

Fixed in r3164